diff --git a/rover.fnl b/rover.fnl
index 6fbdb8f..c0405d7 100644
--- a/rover.fnl
+++ b/rover.fnl
@@ -10,9 +10,12 @@
   (any obstacles
        (fn [[ox oy]] (and (= ox x) (= oy y)))))
 
+(fn lateral? [direction]
+  (. {:w true :e true} direction))
+
 (fn try-to-drive [{: x : y : direction : stopped} distance]
   (let [distance
-        (if (. {:w true :e true} direction)
+        (if (lateral? direction)
             (/  distance (math.cos (/ (* math.pi y) 180)))
             distance)]
     (match direction